The present invention relates to a device for supplying fluid to a tool for breaking hard material, e.g. coal, said tool being mounted in a holder, and that a nozzle is arranged in or in connection to the tool, and that fluid is arranged to be supplied to the nozzle via a first channel in the holder and a second channel in a machine part, e.g. a shearer drum, supporting the holder, said second channel communicating with said first channel.
In devices of this kind fluid is supplied in order to, on one hand, cool the tool and the rock thus reducing the risk for ignition that can cause fire or gas explosion and on the other hand, to limit the presence of dust. High fluid pressures can also assist in breaking the material. Devices of that type are described in German Pat. No. 3307895 and EP-A-10534.
In these known devices fluid can enter between the holder and the machine part. This means high forces on the welded joint between the holder and the machine part and it also means risk for corrosive damages on the contact surfaces between the holder and the machine part.
An aim of the present invention therefore is to provide a device that prevents fluid to enter between the contact surfaces between the holder and the machine part.
Another aim of the present invention is to provide a fluid transmission that imposes no longitudinal force on the tool.